Three-dimensional type I collagen lattices induce coordinate expression of matrix metalloproteinases MT1-MMP and MMP-2 in microvascular endothelial cells.
Matrix metalloproteinases (MMPs) are hypothesized to play a key role in the processes of endothelial cell migration and matrix remodeling during angiogenesis. We utilized an in vitro model of microvascular endothelial cell angiogenesis, cells cultured within a collagen matrix, to investigate the MMP profile of endothelial cells undergoing angiogenesis. We demonstrated by gelatin zymography that monolayer cultures (two-dimensional) of endothelial cells constitutively expressed low levels of latent MMP-2, but that culture in a three-dimensional collagen matrix increased the total amount of MMP-2 mRNA and protein. Furthermore, 51% of total MMP-2 protein was activated in the three-dimensional culture lysates, compared with 3.5% in two-dimensional culture. The mRNA and protein of MT1-MMP, the putative activator of MMP-2, were up-regulated in endothelial cells cultured in three-dimensional as compared with two-dimensional culture. Treatment of cultures with MMP inhibitors blocked activation of MMP-2 and inhibited formation of endothelial cell networks within the collagen gel. Induction of MT1-MMP and MMP-2 appeared to be specific to collagen, inasmuch as culture of the endothelial cells on top of, or within, a Matrigel(R) matrix neither increased total MMP-2 nor increased activation of MMP-2. These results suggest that MT1-MMP activation of MMP-2 occurs in endothelial cells undergoing angiogenesis, that this activation has a functional role in endothelial cell organization, and that specific matrix interactions may be critical for the increased expression of MT1-MMP and MMP-2.
Haas
T L
TL
Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
Davis
S J
SJ
Madri
J A
JA
D000818:Animals; D002478:Cells, Cultured; D003094:Collagen / Q000737:chemistry / Q000378:metabolism*; D004338:Drug Combinations; D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018093:Gelatinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007797:Laminin; D020778:Matrix Metalloproteinase 2; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000187:drug effects; D011487:Protein Conformation; D011509:Proteoglycans; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics / Q000378:metabolism
D004338:Drug Combinations; D004791:Enzyme Inhibitors; D007797:Laminin; D011509:Proteoglycans; D012333:RNA, Messenger; C059485:matrigel; D019716:Tissue Inhibitor of Metalloproteinase-2; D003094:Collagen; D018093:Gelatinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2